Special needs children

I have a cousin who has downs-syndrome. She is very high functioning she wasn't suppose to even live a year. Because of growing up with her I was very exposed to special needs children. Since, I have worked as a paraprofessional teacher for special need children and I now work in a residential house for behavioral special needs children. I haven't beentrying  to conceive but it's Been on my mind a lot lately I have "baby fever" but I can't help but have this feeling that I may have a higher than average chance of having a child with special needs. Which would be a blessing if it did happen, I feel like I have a gift being able to work with special needs, I adore the children. But it's obviously a huge concern and worry that I may have a child with a condition like those that I see on a daily basis. Has anyone ever felt this way? Has anyone that has had a special needs child ever had pre conceived notions that they may have a special needs child before conceiving?